


Mistaken

by himawri45 (kotaka_kun)



Category: Captain America (Movies), Marvel Cinematic Universe
Genre: Alpha!Bucky, Alpha/Beta/Omega Dynamics, M/M, Mating Cycles/In Heat, Omega!Steve, Omegaverse
Language: English
Status: Completed
Published: 2018-06-18
Updated: 2018-06-18
Packaged: 2019-05-24 21:55:38
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,315
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14962901
Author URL: https://archiveofourown.org/users/kotaka_kun/pseuds/himawri45
Summary: He was supposed to have been a Beta. That was supposed to be the end of things. Steve hadn't had a rut or a heat by his 13th birthday, so the only conclusion was that he was a Beta.





	Mistaken

**Author's Note:**

> //Hello! Um can I ask for a silly prompt where Steve is finally having his first heat late in his teens ((except he always thought he was a beta)) and relies on alpha!Bucky to walk/help him through it?//
> 
> cross-posted on [this blog](http://ohmyomegasteveandalphabucky.tumblr.com)

He was supposed to have been a Beta. That was supposed to be the end of things. Steve hadn't had a rut or a heat by his 13th birthday, so the only conclusion was that he was a Beta. His mother said that he might just be a late bloomer, like his father had been. And it wasn't entirely unheard of for someone to present in their midteens, but somehow Steve was doubtful. He didn't care much either way to begin with though, so he was perfectly content with just being a Beta. Even if it was just another thing that classmates gave him a hard time for.

They never tried anything too serious though, how could they, when his best friend was an Alpha like Bucky? Unlike Steve who hadn't known what he'd present as, everyone had known Bucky would be an Alpha. He'd had all the traits of a typical Alpha since day one of kindergarten; it had been obvious from the protectiveness, the perceptiveness, the loyalty that he displayed. There hadn't been a question about it, so no one had been surprised when he missed a week of seventh grade, because he'd gotten his first rut. He was welcomed back with congratulations from his classmates, because by middle school standards, he was a man now, but he'd brushed off the empty compliments and had stuck with Steve as though it was the most natural thing in the world.

It wasn't, and Steve knew it. The other Alphas their age like Rumlow or Rollins took to their designation with pride almost to the point of obsession, and had abandoned their Beta friends as soon as they could. Maybe it was out of fear that something was wrong them if they were hanging around Betas instead of Omegas like they /should/ be, and Steve had always thought that sort of the thing so stupid, but there'd definitely been a feeling of relief when Bucky hadn't let their designation change their friendship in the least.

 

It was just a month or two before his 20th birthday when it happened. It was finals week, and they were in the home stretch of things, and Bucky was due to come over so they could study together, as they'd always done. But that morning, Steve woke up to a roll of nausea coursing through him, and he managed stumble into the bathroom just in time to lean over the toilet as he retched. Not much came up, but he could feel his stomach begin to cramp up painfully as he broke into a cold sweat. He could already tell he was just at the precipice of a fullblown fever, but he'd already had the flu last month, so it couldn't be that, he thought to himself. He went ahead and took a couple of fever reducers before crawling miserably back under the covers, and sending a text to Bucky, apologizing but admitting that he needed to cancel their study session today, lest he give whatever he had to Bucky.

His friend asked if he should bring some soup for lunch, and as grateful as Steve was, he declined the offer. He'd feel terrible if he got Bucky sick during finals, and he said as much, but Bucky just shot back that his immune system was no match for whatever was plaguing Steve. And to be fair, that often seemed to be the case. Bucky would always come by whenever Steve got sick, and yet he never seemed to contract the illness himself, so it either meant that Bucky had a terribly strong immune system, or Steve's was not up to par. Steve liked to think it was the former.

Still, he told Bucky, he didn't want to chance it. Bucky seemed to reluctantly agreed, but Steve knew that he'd probably have a visitor by this afternoon, regardless, so he settled in and tried to get some rest.

The cramps were getting unbearable as the hours dragged on, however, to the point where Steve couldn't possibly hope to get any rest, and had to wonder if he was dying. The medicine hadn't done a thing for his fever, and even the soft fabric of his comfiest pajamas he wore felt too rough and scratchy on his skin. Everything felt too warm, too tight, too restricting, so in a latch ditch attempt to get comfortable, he stripped down to his underwear, but it didn't quite seem to do the trick. He was starting to get desperate, and quite frankly, he was past being a little scared. Never before when he'd been sick had things felt so...  _ intense _ before. Which was saying something, considering that he'd had just about every illness one could get without dying, and then some close calls on top of that.

And that was when he heard Bucky knock. For a moment he contemplated how he should go and open the door for his friend, only to realize a moment later that there was no need to -- Bucky was using the copy of Steve's apartment key they left under the doormat to let himself in.

"Steve," Bucky's voice came, muffled a little by his closed bedroom door, "You awake? Brought you soup and some other stuff." Other stuff probably being fever reducers and decongestants and all of that. Bucky was always so good about keeping Steve's medicine cabinet stocked.

Steve opened his mouth with every intention to call out a quick thanks, but instead, all he got out was a whimper. Bucky's scent suddenly hit him full force, and  _ God _ , he smelled good. Warm. Safe. And Steve needed him.

Bucky walked in not a minute later, and Steve couldn't help the way he was moving to bury his face in his hands, wiggling his hips up ever so slightly -- it was like his body was moving of its own volition, and he couldn't do anything about it.

He was  _ presenting _ .

Christ, he was an Omega, wasn't he?

"Stevie, what-" Bucky sounded choked. Steve could only imagine how thick his own scent must be to his Alpha friend.

"'M sorry, Buck,  _ please _ ," It would be a lie to say that Steve wasn't sure what he was asking for, but he didn't know how else to ask, "Please, Buck, I- I need you." He was just so  _ empty _ and he  _ needed _ Bucky.

Clearly, Bucky didn't need to be told twice. His pupils were blown, and Steve could already see his cock straining in his pants. Letting out a content sound into his arms as Bucky mounted him, Steve wiggled his hips eagerly.

And then everything was good,  _ so _ good, too much and not enough all at once. It was like sparks were going off just under his skin, his veins flooded with fire that burned in the best way. He was probably begging for more, for Bucky's knot, but he couldn't be sure. Bucky didn't hold back, and when he came, Steve keened as he felt Bucky fill him up and knot him.

"I don't get it," Bucky breathed, when he was finally able to slide out of Steve, "I thought you were a Beta."

"'M just as confused as you." Steve croaked, whining when he felt the bed dip in a way that could only mean Bucky was getting out of bed.

"I'm just gonna get you something to drink, okay?" Bucky assured him immediately, coming round to his side of the bed and pressing a light kiss to his forehead. Steve felt his face flush from embarrassment despite the fact that Bucky had been inside him just moments ago. "And maybe something to eat." he added with a grin when Steve's stomach growled. "Let me take care of you, hm? We can talk about this afterwards."

Steve nodded sheepishly, and watched Bucky shuffle off to the kitchen.

Bucky had always been good with taking care of him.

**Author's Note:**

> sorry if the ending felt abrupt,, but hey!!  
> it's been a hot minute, but tomorrow (today?) marks one year since I spent eight hours reading a glorious stucky fic that absolutely positively changed the course of my life, no joke. I love this ship so much, and it's wonderful content creators. so thanks for reading, leaving kudos, a comment -- any and all of it. this fandom is what's kept me going, and I'm seriously so happy to be here.
> 
> come keep me company on [tumblr](http://kotaka-kun.tumblr.com)!!


End file.
